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BACKGROUND After heart transplantation, respiration-synchronous fluctuations (0.18 to 0.35 Hz, high frequency [HF]) in RR interval may result from atrial stretch caused by changes in venous return, but slower fluctuations (0.03 to 0.15 Hz, low frequency [LF]) not due to respiration suggest reinnervation. In normal subjects, sinusoidal neck suction(More)
1. To assess the effects of acute exposure to high altitude on baroreceptor function in man we evaluated the effects of baroreceptor activation on R-R interval and blood pressure control at high altitude. We measured the low-frequency (LF) and high-frequency (HF) components in R-R, non-invasive blood pressure and skin blood flow, and the effect of(More)
OBJECTIVES To assess whether talking or reading (silently or aloud) could affect heart rate variability (HRV) and to what extent these changes require a simultaneous recording of respiratory activity to be correctly interpreted. BACKGROUND Sympathetic predominance in the power spectrum obtained from short- and long-term HRV recordings predicts a poor(More)
The discovery of cardiac natriuretic hormones required a profound revision of the concept of heart function. The heart should no longer be considered only as a pump but rather as a multifunctional and interactive organ that is part of a complex network and active component of the integrated systems of the body. In this review, we first consider the(More)
OBJECTIVE To assess the influence of different breathing patterns on autonomic cardiovascular modulation during acute exposure to altitude-induced hypoxia. DESIGN We measured relative changes in minute ventilation (VE), oxygen saturation (%SaO2), spectral analysis of RR interval and blood pressure, and response to stimulation of carotid baroreceptors(More)
1. We have tested the hypothesis that the non-respiratory, low-frequency (around 0.1 Hz) fluctuations of heart rate variability are generated by the baroreflexes, but with a delay caused by the slower response of the efferent sympathetic arm, (compared with the vagus), in 11 healthy subjects (mean age +/- SD 27 +/- 5 years). 2. In random order, at the onset(More)
To determine whether skin blood flow is local or takes part in general regulatory mechanisms, we recorded laser-Doppler flowmetry (LDF; left and right index fingers), blood pressure, muscle sympathetic nerve activity (MSNA), R-R interval, and respiration in 10 healthy volunteers and 3 subjects after sympathectomy. We evaluated 1) the synchronism of LDF(More)
AIMS Serum gamma-glutamyl transferase activity (gamma-GT) is able to catalyse low-density lipoprotein oxidation and has been detected in coronary atherosclerotic plaques. gamma-GT has been documented as an independent risk factor for cardiac mortality in middle-aged men. The purpose of this study is to determine the prognostic value of gamma-GT in patients(More)
Elevation of serum gamma-glutamyltransferase (GGT) activity is a risk factor for myocardial infarction and stroke. GGT activity can catalyze the oxidation of low-density lipoprotein (LDL), a process involved in the pathogenesis of atherosclerosis. Serum GGT is partially adsorbed onto circulating LDL, and catalytically active GGT has been found within(More)
OBJECTIVE The aim of this study was to investigate the influence of circadian behavior of blood pressure, left ventricular hypertrophy, and autonomic function on QTc interval duration in untreated hypertensive patients. DESIGN Hypertensive patients underwent simultaneous blood pressure and ECG 24-h ambulatory monitoring. Patients were classified into two(More)